Morris Minor Owners Club

Well dare I suggest that the system was designed for the car they were building, as works fine in those circumstances.
If Morris had altered it by fitting a 1275, perhaps the extra demand on the fuel system would have resulted in other relevant changes.
That's what often comes with Owner Modifications, few people consider the bigger picture.
You've identified that for your circumstances, it 'could be better'; so perhaps your installation might benefit from a rear mounted HP pump, rather than the forward mounted LP one...
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I've been involved in racing for over 40 yrs, with all due respect there isn't much on a minor that was well engineered lol, hence why modern cars have evolved. I see it makes no difference that I have a 1275 engine as its just a pump , as long as it flows enough gph and gives the right pressure for the engine that's fitted , I'd be interested to knowhow you have come up with your theory especially as a few people have said they have had issues with too much pressure.
Personally I think the position of the pump is right above the exhaust will always have heat issues .

Harryhotrod wrote: ↑Sun Aug 03, 2025 6:27 pm
I've been involved in racing for over 40 yrs, with all due respect there isn't much on a minor that was well engineered lol, hence why modern cars have evolved. I see it makes no difference that I have a 1275 engine as its just a pump , as long as it flows enough gph and gives the right pressure for the engine that's fitted , I'd be interested to knowhow you have come up with your theory especially as a few people have said they have had issues with too much pressure.
Personally I think the position of the pump is right above the exhaust will always have heat issues .

The Minor is of it's period, and engineered as such; your remark about modern cars having 'evolved' is somewhat deprecating to the designers of 80 years ago.
The Minor was a massive leap forward in design compared the cars the late 1930s!

I don't know of people who have complained of too much pressure, not from an SU at least, because the SU fuel pump was matched with the SU Carb for pressure requirements.

I've only had my Minor 8 years, it's a SII with a 1098, but I've never had issues with the fuel system, i.e. vapour lock etc, despite long runs in recent summers....

The only thing I have ever noticed with regard to the pump is that in very hot weather it ticks faster, but if that is caused by vapourisation, its never been enough to affect the running of the car at all.

I suppose many haven’t even considered the changes in fuel formulation over the years. The proportion of lower-carbon-chain hydrocarbons is far different than fuel of decades past. The original SU pump was, and still is, perfectly adequate for the vehicle over the last several decades, IMO. I might have reservations under certain conditions, but I’ve never encountered any such extreme situations.

"I suppose many haven’t even considered the changes in fuel formulation over the years."
No, I don't suppose they have.......

True but the basic design predates the Minor and is pre-war. The pumps survived massive variation in the quality of fuel as I am sure my father would have told me. Ethanol is nothing new!

Stephen

"Ethanol is nothing new!"
No, you're right, it isn't, we've been drinking it for years in beer, wine, spirits etc!

myoldjalopy wrote: ↑Mon Aug 04, 2025 12:23 pm "Ethanol is nothing new!"
No, you're right, it isn't, we've been drinking it for years in beer, wine, spirits etc!

https://youtu.be/4uEqqlqqf4Q

https://www.gracesguide.co.uk/Cleveland_Discol

I think I'd draw the line at drinking petrol, no matter how much alcohol was mixed with it!